Fermi surfaces in Kondo insulators

Hsu Liu, Máté Hartstein, Gregory J Wallace, Alexander J Davies, Monica Ciomaga Hatnean, Michelle D Johannes, Natalya Shitsevalova, Geetha Balakrishnan, Suchitra E Sebastian
2018 Journal of Physics: Condensed Matter  
We report magnetic quantum oscillations measured using torque magnetisation in the Kondo insulator YbB$_{12}$ and discuss the potential origin of the underlying Fermi surface. Observed quantum oscillations as well as complementary quantities such as a finite linear specific heat capacity in YbB$_{12}$ exhibit similarities with the Kondo insulator SmB$_6$, yet also crucial differences. Small heavy Fermi sections are observed in YbB$_{12}$ with similarities to the neighbouring heavy fermion
more » ... heavy fermion semimetallic Fermi surface, in contrast to large light Fermi surface sections in SmB$_6$ which are more similar to the conduction electron Fermi surface. A rich spectrum of theoretical models is suggested to explain the origin across different Kondo insulating families of a bulk Fermi surface potentially from novel itinerant quasiparticles that couple to magnetic fields, yet do not couple to weak DC electric fields.
doi:10.1088/1361-648x/aaa522 pmid:29300180 fatcat:fgexvcjtqvehnn4ks4q66jkska